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Abstract:

It is possible to provide a small-size and light-weight control device
having a structure which prevents detaching of a board even when an
external shock is applied without using a screwed connection. The control
device is formed by a case including at least one board, a radiator, and
a protection cover. The case includes at least one latch portion in an
upper part or a lower part of a board support frame.

Claims:

1. A control device comprising a case, the case including at least one
board and a radiator, wherein the case includes at least two latch
portions with different heights in an upper part or a lower part of a
board support frame.

2. The control device according to claim 1, wherein at least one pillar
is included on a side of the latch portion.

3. The control device according to claim 1, wherein the case includes
board support frames, a pair of opposing board support frames including
latch portions for fixing at least one of the boards, and another pair of
opposing board support frames including latch portions for fixing the
board stacked on the at least one of the boards.

4. A control device comprising a case, the case including at least one
board and a radiator, wherein the case includes at least one latch
portion in an upper part or a lower part of a board support frame, and
wherein the board disposed on the top includes a rib being in contact
with a pillar included in the case.

5. The control device according to claim 1, wherein the board disposed on
the top includes a rib being in contact with a pillar included in the
case.

6. A control device comprising a case, the case including at least one
board and a radiator, wherein the case includes at least one latch
portion in an upper part or a lower part of a board support frame, and
wherein the latch portion engaged with an elastic hole included in the
case also serves as a pillar for supporting the board.

7. The control device according to claim 1, wherein the latch portion
engaged with an elastic hole included in the case also serves as a pillar
for supporting the board.

Description:

[0001] This application is a division of application Ser. No. 12/444,503
filed Apr. 6, 2009, which is hereby incorporated by reference in its
entirety.

TECHNICAL FIELD

[0002] The present invention relates to a control device for operating an
industrial appliance.

BACKGROUND ART

[0003] Two types of control devices have been proposed. In a first
example, components are fixed with screws (see, for example, Patent
Document 1). In a second example, components are mounted from one
direction without using screws (see, for example, Patent Document 2).

[0004] Referring to FIG. 11, the first existing example is described. As
shown in FIG. 11, a control device is constructed by placing a printed
circuit board 102 on a base 103, screwing a screw 119 into a through hole
113 in the printed circuit board 102 and a screw hole 106 in a board
mounting boss 107 so as to fasten the printed circuit board 102 to the
base 103, joining a fitting protrusion in an inner cover mounting boss
109 of the base 103 to a fitting recess in a boss 116 on an inner cover
104, pinching the printed circuit board 102 with the inner cover 104,
fastening the inner cover 104 with screws 120, and covering the entire
base 103 with a cover 105.

[0005] Referring to FIGS. 12 and 13, the second existing example is
described. As shown in FIG. 12, an existing control device is assembled
as follows. First, an LCD case 210 is fixed to a back surface or another
part of a printed circuit board 202 with connecting pieces 211c by
soldering or the like. Next, as indicated by arrow A in FIG. 13, a side
plate 213 of an LCD cover 212 is hooked to bent portions 211b of a side
plate 211 of the LCD case 210, an LCD cover 212 is rotated around the
hooked portion as indicated by arrow B in the figure, and notches 213a in
another side plate 213 of the LCD cover 212 are engaged with other bent
portions 211a. By moving the LCD cover 212 in this state, the bent
portions 211a and the notches 213a are engaged with each other, and the
LCD case 210 is engaged with the LCD cover 212, whereby assembly is
completed.

[0008] Control devices are broadly used in the fields of robots, machine
tools, automobiles, and the like. High reliability and ease of
maintenance are required for a control device, while reduction in size
and weight is also desired. Thus, by changing the mounting structure of a
control device from a two-dimensional structure to a three-dimensional
structure, the space for disposing the control device is efficiently
used. However, in the mounting structure of a board, electronic
components are densely mounted on the board, the areas to which stacked
boards are attached are limited, and it has been desired that a control
device be configured such that the boards are not separated even when an
external shock is applied.

[0009] However, because an existing control device is configured such that
stacked boards are fastened with screws, it is necessary to secure a
space and an insulation distance for fastening the screws, thereby
causing a problem in that reduction in size is hindered. Moreover, there
is a problem with fastening using screws in that the screws may be
loosened by repeated vibrations or shocks and the boards may fall off.
Furthermore, there is a problem in that workability is reduced because it
is necessary to remove the screws in order to carry out maintenance of
the boards.

[0010] In addition, in the case of a top mounting method in an existing
control device, there is a problem in that the number of parts increases
because parts are used among the components. When the number of parts
increases, reduction in size and weight becomes unfeasible, which causes
a problem in that the control device has to be disposed in a larger
space.

[0011] The present invention, which has been achieved to overcome the
problems, aims to provide a control device having a structure with which
the number of parts is reduced, reduction in the size and weight of the
control device is realized, and boards are prevented from falling off
when an external shock is applied without using a screw connection.

Means for Solving the Problems

[0012] In order to solve the above-described problems, the present
invention is configured as follows.

[0013] In the invention according to a first aspect, a control device
comprises a case, the case including at least one board and a radiator,
wherein the case includes at least one latch portion in an upper part or
a lower part of a board support frame.

[0014] In the invention according to a second aspect, the case includes
pillars disposed in four corners and the board support frame connecting
the pillars.

[0015] In the invention according to a third aspect, the case includes
board support frames, a pair of opposing board support frames including
latch portions for fixing a first board, and another pair of opposing
board support frames including latch portions for supporting a second
board.

[0016] In the invention according to a fourth aspect, the first board is
engaged with the latch portions included in the upper parts of the board
support frames and the second board is engaged with the latch portions
included in the lower parts of the board support frames.

[0017] In the invention according to a fifth aspect, the case includes
board support frames, a pair of opposing board support frames including
latch portions for fixing a first board in upper parts thereof and
elastic holes for supporting a second board in lower parts thereof.

[0018] In the invention according to a sixth aspect, at least one guide
notch portion for positioning the board with respect to the case is
formed in an outer peripheral surface of the board.

[0019] In the invention according to a seventh aspect, a latch portion for
positioning the radiator with respect to the case is formed in an outer
peripheral surface of the radiator.

[0020] In the invention according to an eighth aspect, the radiator
includes a board including a cooling fan.

[0021] In the invention according to a ninth aspect, the control device
further comprises a protective cover, wherein at least one recess is
formed in an outer peripheral surface of the protective cover and engaged
with the latch portion of the case.

[0022] In the invention according to a tenth aspect, a control device
comprises a case including at least one board and a radiator, wherein the
case includes at least two latch portions with different heights in an
upper part or a lower part of a board support frame.

[0023] In the invention according to an eleventh aspect, at least one
pillar is included on a side of the latch portion.

[0024] In the invention according to a twelfth aspect, the case includes
board support frames, a pair of opposing board support frames including
latch portions for fixing at least one of the boards, and another pair of
opposing board support frames including latch portions for fixing the
board stacked on the at least one of the boards.

[0025] In the inventions according to a thirteenth aspect and a fourteenth
aspect, the board disposed on the top includes a rib being in contact
with a pillar included in the case.

[0026] In the inventions according to a fifteenth aspect and a sixteenth
aspect, the latch portion engaged with an elastic hole included in the
case also serves as a pillar for supporting the board.

ADVANTAGES

[0027] With the inventions according to the first to sixteenth aspects,
because the boards are fixed without using fastening members such as
screws, the number of parts can be reduced and the boards are prevented
from falling off even when an external shock is applied. Moreover,
because the boards are configured to be supported with the latch portions
and the elastic holes, assembling and disassembling can be carried out
easily, whereby workability in maintenance is improved. Moreover, because
the boards can be assembled and removed from above or below the case,
workability is improved without increasing the number of parts.
Furthermore, because the plurality of boards can be supported by
providing the plurality of latch portions of different heights,
expandability is high and space can be efficiently used.

[0028] In particular, with the inventions according to the eleventh aspect
and the thirteenth to sixteenth aspects, the boards are prevented from
falling off with external shocks or vibrations, because the pillars and
the ribs for fixing the boards are formed so as to hold the boards more
securely.

BRIEF DESCRIPTION OF DRAWINGS

[0029] FIG. 1 is an exploded perspective view of a control device
according to a first embodiment of the present invention.

[0030]FIG. 2 is an exploded perspective view of the control device
according to the first embodiment of the present invention.

[0031]FIG. 3 is an assembled perspective view of the control device
according to the first embodiment of the present invention.

[0032]FIG. 4 is an exploded perspective view of a control device
according to a second embodiment of the present invention.

[0033]FIG. 5 is an assembled perspective view of the control device
according to the second embodiment of the present invention.

[0034]FIG. 6 is an assembled perspective view of a control device
according to a third embodiment of the present invention.

[0035]FIG. 7 is a sectional view of a control device according to a
fourth embodiment of the present invention.

[0036]FIG. 8 is an enlarged view of the control device according to the
fourth embodiment of the present invention.

[0037]FIG. 9 is an assembled perspective view of a control device
according to a fifth embodiment of the present invention.

[0038]FIG. 10 is an enlarged view of a rib of the control device
according to the fifth embodiment of the present invention.

[0039] FIG. 11 is an exploded perspective view of a first existing control
device.

[0040] FIG. 12 is an exploded perspective view of a second existing
control device.

[0041] FIG. 13 is a side view of a second existing control device.

REFERENCE NUMERALS

[0042] 1 case

[0043] 2 first printed circuit board

[0044] 3 second printed circuit board

[0045] 4 protective cover

[0046] 5 radiator

[0047] 6 heat conductive sheet

[0048] 7 first latch portion

[0049] 8 second latch portion

[0050] 9 guide notch portion

[0051] 10 guide notch portion

[0052] 11 third latch portion

[0053] 12 recess

[0054] 13 elastic hole

[0055] 14 latch portion

[0056] 15 pillar/board positioning portion

[0057] 16 board support frame

[0058] 17 cooling fan plate

[0059] 20 latch portion

[0060] 21 case

[0061] 22 first latch portion

[0062] 23 second latch portion

[0063] 24 third latch portion

[0064] 25 fourth latch portion

[0065] 26 first printed circuit board

[0066] 27 second printed circuit board

[0067] 28 third printed circuit board

[0068] 29 fourth printed circuit board

[0069] 30 guide notch portion

[0070] 31 guide notch portion

[0071] 32 guide notch portion

[0072] 33 guide notch portion

[0073] 34 first pillar

[0074] 35 second pillar

[0075] 36 board support frame

[0076] 41 rib

[0077] 102 printed circuit board

[0078] 103 base

[0079] 104 inner cover

[0080] 105 cover

[0081] 106 screw hole

[0082] 107 board mounting boss

[0083] 109 inner cover mounting boss

[0084] 113 through hole

[0085] 116 boss

[0086] 119 screw

[0087] 120 screw

[0088] 202 printed circuit board

[0089] 210 LCD case

[0090] 211 side plate

[0091] 211a bent portion

[0092] 211b bent portion

[0093] 211c connecting piece

[0094] 212 LCD cover

[0095] 213 side plate

[0096] 213a notch

BEST MODES FOR CARRYING OUT THE INVENTION

[0097] Hereinafter, embodiments of the present invention are described
with reference to the drawings.

First Embodiment

[0098] FIG. 1 is an exploded view showing a structure of a control device
for carrying out a method of the present invention. The figure shows a
case 1, a first printed circuit board 2, a second printed circuit board
3, a protective cover 4, and a radiator 5.

[0099] The present invention is different from Patent Document 1 and
Patent Document 2 in that the case includes latch portions for fixing the
boards to be stacked, the latch portions being disposed in an upper part
or a lower part of board support frames of the case.

[0100] The case 1 includes pillar/board positioning portions 15 in the
four corners thereof, each of the pillar/board positioning portions 15
being connected with board support frames 16 by adhesion or the like.
Alternatively, the pillar/board positioning portions 15 and the board
support frames 16 are integrally formed. Elastic holes 13 are formed in
lower parts of a pair of board support frames 16, and third latch
portions 11 are formed in upper parts of the pair of board support frames
16. First latch portions 7 and second latch portions 8 are formed in
upper parts and lower parts of another pair of board support frames 16.

[0101] Next, the first printed circuit board 2 is described. Guide notch
portions 9 are formed in an outer peripheral surface of the first printed
circuit board 2 so that the first printed circuit board 2 is positioned
with respect to the case 1.

[0102] The second printed circuit board 3 is described. Guide notch
portions 10 are formed in an outer peripheral surface of the second
printed circuit board 3 so that the second printed circuit board 3 is
positioned with respect to the case 1.

[0103] The radiator 5 is described. Latch portions 14 are formed on a pair
of sides of an outer peripheral surface of the radiator 5 so as to be
engaged with the elastic holes 13 of the case 1.

[0104] Next, referring to FIGS. 1, 2, and 3, an assembly process of the
control device is described. First, the second printed circuit board 3 is
inserted into the case 1 such that the guide notch portions 10 formed in
four positions in the outer peripheral surface are positioned along the
second latch portions 8 formed in the case 1, and the second printed
circuit board 3 is fixed with the second latch portions 8 of the case 1.

[0105] Next, the first printed circuit board 2 is inserted into the case 1
such that the guide notch portions 9 formed in four positions in the
outer peripheral surface are positioned along the first latch portions 7
formed in the case 1, and the first printed circuit board 2 is fixed with
the first latch portions 7 of the case 1.

[0106] Next, the radiator 5 is fixed by engaging the latch portions 14
formed on the outer peripheral surface with the elastic holes 13 of the
case 1.

[0107] Next, regarding the protective cover 4, recesses 12 formed in its
outer peripheral surface are fixed with the third latch portions of the
case 1.

Second Embodiment

[0108] Next, referring to FIGS. 4 and 5, a second embodiment of the
present invention is described. The present invention is different from
the first embodiment in that a plurality of latch portions are formed in
an upper part and a lower part of the board support frames of the case so
that three or more printed circuit boards can be fixed.

[0109] Differences from the first embodiment are described. In a case 21,
first latch portions 22 and second latch portions 23 are formed in upper
parts and lower parts of a pair of board support frames 36. Third latch
portions 24 and fourth latch portions 25 are formed in upper parts and
lower parts of another pair of board support frames 36. Moreover, first
pillars 34 and second pillars 35 are formed adjacent to the third latch
portions 24 and the fourth latch portions 25.

[0110] Next, referring to FIGS. 4 and 5, an assembly process is described.
First, a second printed circuit board 27 is inserted into the case 21
such that guide notch portions 31 formed in four positions in the outer
peripheral surface are positioned along the second latch portions 23
formed in the case 21, and the second printed circuit board 27 is fixed
with the second latch portions 23 of the case 21.

[0111] Next, a first printed circuit board 26 is inserted into the case 21
such that guide notch portions 30 formed in four positions in the outer
peripheral surface are positioned along the first latch portions 22
formed in the case 21, and the first printed circuit board 26 is fixed
with the first latch portions 22 of the case 21.

[0112] Next, a fourth printed circuit board 29 is inserted into the case
21 such that guide notch portions 33 formed in four positions in the
outer peripheral surface are positioned along the fourth latch portions
25 formed in the case 21, and the fourth printed circuit board 29 is
fixed with the fourth latch portions 25 of the case 21. At this time, the
fourth printed circuit board 29 is fixed while being supported by the
second pillar 35.

[0113] Next, a third printed circuit board 28 is inserted into the case 21
such that guide notch portions 32 formed in four positions in the outer
peripheral surface are positioned along the third latch portions 24
formed in the case 21, and the third printed circuit board 28 is fixed
with the third latch portions 24 of the case 21. At this time, the third
printed circuit board 28 is fixed while being supported by the first
pillars 34.

[0114] In the embodiment described here, latch portions of different
heights are disposed in pairs on board support frames. However, latch
portions of different heights may be disposed on the same board support
frame. Needless to say, that latch portions of different heights may be
disposed, for example, on a pair of opposing board support frames. The
embodiment is described using an example having four printed circuit
boards. However, needless to say, four or more printed circuit boards can
be stacked by forming latch portions of different heights. Not only
printed circuit boards, but also a combination of radiators and
protective covers can be stacked.

Third Embodiment

[0115] Next, referring to FIG. 6, a third embodiment of the present
invention is described. The third embodiment is different from the first
embodiment and the second embodiment of the present invention in that
elastic holes are formed in a pair of upper parts of an outer peripheral
surface of a case so as to fix a cooling fan plate.

[0116] As shown in FIG. 6, a cooling fan plate 17 has latch portions 20
formed in a pair of sides of an outer peripheral surface thereof, and the
cooling fan plate 17 is disposed such that the latch portions 20 are
fixed to elastic holes 13 formed in a pair of upper parts of an outer
peripheral surface of a case 1.

Fourth Embodiment

[0117] Next, referring to FIGS. 7 and 8, a fourth embodiment of the
present invention is described. The fourth embodiment is different from
the first to third embodiments of the present invention in that latch
portions of a radiator fixed to elastic holes formed in a pair of lower
parts of an outer peripheral surface of a case also serve as pillars for
supporting a board positioned above.

[0118]FIG. 7 shows a sectional view of a control device, and FIG. 8 shows
an enlarged view of a latch portion. Latch portions 8 formed in a
radiator 5 are fit into elastic holes 13 of a case 1, and the radiator 5
is fixed to the case 1. At this time, the latch portions 8 are disposed
so that the latch portions 8 support the bottom surface of the second
printed circuit board 3 and fix the second printed circuit board 3.

[0119] Although the latch portions are formed in the radiator and fitted
into the elastic holes in the case so that the printed circuit board is
supported from the bottom, it is not necessary that the latch portions be
formed in the radiator. The latch portions may be formed in a component
attached to the case, such as a printed circuit board or a protective
cover. Moreover, although the radiator including the latch portions is
disposed at the lowermost position in the configuration described here,
it is not necessary that the latch portions be disposed at the lowermost
position. It is evident that a board including the latch portions may be
a board in the middle of the stack.

Fifth Embodiment

[0120] Next, referring to FIGS. 9 and 10, a fifth embodiment of the
present invention is described. The fifth embodiment is different from
the first to fourth embodiments of the present invention in that ribs are
formed on a cover in contact with the pillar/board positioning portions
in the four corners of the case.

[0121]FIG. 9 shows a perspective view of the control device, and FIG. 10
shows an enlarged view of a rib portion. Ribs 41 are formed on a
protective cover 4, and a surface of the each rib 41 is disposed in
contact with a corresponding pillar/board positioning portion 15 in a
case 1. By doing so, falling off is prevented due to a supporting effect
of the ribs 41.

INDUSTRIAL APPLICABILITY

[0122] The present invention is also applicable to a multi-axis control
device, because the number of stacks can be increased by increasing the
number of latch portions and pillars on the board support frames.